A declarative framework for constrained search problems

Abstract

Constrained search problems (eg. scheduling, planning, resource allocation, placement, routing etc.) appear frequently at different levels of decisions. They are usually characterized by many types of constraints, which make them unstructured and difficult to solve (NP-complete). Traditional mathematical programming approaches are deficient because their representation of constraints is artificial (using 0-1 variables). Unlike traditional approaches, constraint logic programming (CLP) provides for a natural representation of heterogeneous constraints. In CLP we state the problem requirements by constraints; we do not need to specify how to meet these requirements. In this paper we propose a declarative framework for decision support system (DSS) for constrained search problems implemented by CLP and relational SQL database. We illustrate this concept by the implementation of a DSS for scheduling problems with external resources in different production organization environments. © 2008 Springer-Verlag Berlin Heidelberg.